Controlling increased epidermal proliferation is a goal of successful treatment for psoriasis. 1,25 Dihydroxyvitamin D3 (Calcitriol) inhibits proliferation and enhances differentiation including keratinocytes. After treating 10 psoriasis patients (in another study) with oral Calcitriol, with mild to moderate clinical response, we studied the degree to which topical Calcitriol treatment might also be efficacious.